Hydraulic grain unloading and washing system



A ril 15, 1958 c, A EN 2,830,702

HYDRAULIC GRAIN UNLOADING AND WASHING SYSTEM Filed May 1, 1955 1N VENTOR.

nited States Patent Ofiice 2,830,702 Patented Apr. 15, 1958 HYDRAULICGRAIN UNLOADING AND WASHING SYSTEM Carl Hagen, Chicago, Ill.

Application May 1, 1953, Serial No. 352,546

4 Claims. (Ci. 209-1) This invention relates to a novel method for theunloading and simultaneous washing of leguminous grain. My invention isparticularly adapted for the unloading and washing of corn and soy beankernels.

One object of this invention is to provide means for unloading grainfrom box cars under conditions wherein no dust is produced. 7

Another object is to provide a grain unloading systern whichsubstantially eliminates grain breakage.

Still another object is to provide a grain unloading and simultaneouswashing system which removes rodent excretions much more completely thanthat which is possible with present day commercial grain unloading andcleaning systems.

In present day grain unloading procedure, such materials as corn kernelsor soy beans are unloaded from box cars with either manually operatedpower shovels or airveyor nozzles. The grain is unloaded into hoppersfrom where it is conveyed to grain cleaners which are supposed to removedut, red eye and rodent excretions. From the grain cleaners, thematerial is conveyed to either storage bins or into the grain processingsystem. During this whole period, namely, from the time the grain leavesthe box cars up to the time wherein it enters a grain processing systemsuch as dry milling, wet milling or cereal flake manufacture,considerable dust formation takes place. This grain dust has a highexplosion hazard and it is necessary to resort to elaborate, expensivedust collecting systems to minimize this hazard. In addition to the dustfactor, a considerable amount of grain breakage takes place, withresultant deleterious effects on subsequent grain processing. Themechanical, pneumatic air cleaning devices used to remove dust androdent offal are unable to alfect a complete removal of theseobjectionable grain impurities. Insect residues and other minute ofralmatter is particularly difiicult to eliminate and frequently grain whichhas been cleaned by these usual dry pneumatic methods contain asufficiently large amount of objectionable residues to be rejected aftergovernment inspection.

In accordance with this invention, I overcome the difficulties inherentin a dry pneumatic grain cleaning system by providing an efiicienthydraulic unloading and washing system. The principle of my process isthe utilization of high pressure water streams as a means for removinggrain from a box car and also as a means for effecting a much moreefficient separation of grain kernels from duts and offal. As soon asthe grain has been thus thoroughly Washed, a stream of hot air isapplied to instantly remove the residual water from the outer grainsurface. The grain is exposed to water contact for only a short periodof time and substantially none of the water penetrates the graininterior.

in carrying out my process, grain is unloaded from a box car by means ofa high pressure water nozzle placed on a platform in front of the boxcar door. The nozzle can be directed in any direction into the box carand this is done until all of the grain is removed. The box car shouldbe slightly pitched so as to facilitate water drainage and grain flow.

The grain flows out of the box car in a steady stream due to the largevolume of water. It is then passed over gratings or rifiies which removethe larger non-grain particles and allow the grain to pass through. Thegrain and water then drop onto a scalping screen wherein the smallernon-grain foreign particles are removed and the grain passes throughthis screen and onto washing screens. Here, high pressure water nozzlesusing clean water wash out the dust and rodent excretions as well asinsect fragments through the screen openings, leaving the grain cleanbut wet and dewatered. The grain now passes over a magnetic pulley wheremetal particles are removed. The wet grain is then spouted through avertical Redler or bulk flow grain conveyor equipped with perforatedstainless steel screens placed at the center of the vertical conveyorcasing. A rapid stream of hot air is blown through these screenperforations. This instantly dries the wet grain as it is moving upwardsin the conveyor. When the grain reaches the desired distributing pointfor processing, it is thoroughly cleaned and the grain surfacethoroughly dried.

No dust collecting system is required. As soon as one car has beenemptied and the next loaded car placed in an inclined unloadingposition, the empty car is placed in front of the dryer where a streamof high temperature air is blown in every direction until the car isdried out. The Water used for unloading the grain, plus the washingwater, is pumped to cleanup screens where it drains to a storage tankand is subsequently used over again. The residue collected on top of theclean-up screen are conveyed to a flash drier and the dried materialused for feed.

Example Referring to the drawing, the box car 1 which is loaded withcorn is placed in a tilted or pitched position as indicated by inclinedfreight car track and wheels at 2. Water from the pressure nozzle 3 isdirected into the grain of the box car. This causes a mixture of waterand grain to flow out of the box car and drop onto the riifie 4 whichcontains metal panels spaced about one inch apart. The corn and waterpass through these open spaces and non-grain material having a widthgreater than one inch is eliminated.

The water and partially cleaned corn drops onto the inclined, vibratingscalping screen 5 which consists of a trough which is about ten feetlong, five feet wide and which is covered with a screen having openingsof about one-half inch diameter. The corn and Water pass through thisscreen and non-grain material larger than the screen openings iseliminated. The stream of corn kernals now drops onto a Washing screen6. This comprises an inclined vibrating trough equipped with a stainlesssteel screen having 7 inch diameter openings. High pressure waternozzles 7 and 8 operating at a pressure of about 50 p. s. i. cause theremoval of fine dust, rodent ofial and insect fragments from the surfaceof the corn kernel. These materials pass through the washing screenwhile the washed corn remaining on top of the screen is moved onto thebelt conveyor 9 equipped at its end with a mag netic pulley 10. As thewet corn passes over the magnetic pulley, metal impurities are removed.

At the end of the belt conveyor 9 the wet corn is vertically transportedby means of a Redler or other type of bulk flow conveyance device 11.Vertical perforated stainless steel screens 12 and 13 are placed on thetwo sides of the conveyor casing. These perforated screens are ten feethigh. As the grain moves vertically upwards in the conveyor, the wetcorn kernels in the perforated screen area 14 are met by a strong blastof current of hot, dry air coming from 15. The air temperature should bewithin a range of 150 to 250 F. and the rate of air flow should be about3500 cubic feet per minute. This will be sufficient to cause the instantdrying of the wet corn kernels as they pass the perforated section 14.The air heating system can be any convenient type. The drawing shows aheating system comprising steam coils 16, air damper 17, and air filter18. When the instantly dried corn kernels leave the vertical conveyor at19, they can be distributed to storage bins or directly into a millingprocess.

A steam coil air heating system 20 is used to supply a blast of 300 F.air at 21 to cause the rapid drying of the box car as soon as all of thecorn has been removed by the water nozzles 3.

The mixture of grain dust, dispersed offal and water which leaves thewashing screen 6 at 22 is pumped to clean-up screens 23 equipped with#17 silk screens. The mixture of water and dispersed offal going throughthe silk screen drops into tank 24. The fine grain dust remains on topof the silk screen 23 and is passed by screw conveyor 25 into a mixer26. Here it is blended with a part of dry material produced by the flashdryer 27. The mixture then drops into the flash dryer 27 and is thenblow into cyclone 28. The dried material is then moved by the conveyor29 to a feed bagging station. Material collected in the dust collector30 is returned to the screw conveyor 29. The flash dryer 27 utilizes thehot air 31 coming from the wet corn drying section in the verticalconveyor at 14. The water in tank 24 is recirculated through pump 32.back to the water nozzle 3. Sediment deposited at the bottom of tank 24is dumped to the sewer at 33.

In corn wet milling plants, the loss from corn breakage during dryunloading and pneumatic cleaning averages about 0.75 lbs. per bushel ofcorn. With my wet unloading process these losses are reduced to 0.25lbs. per bushel.

In dry corn milling plants such as corn flakes or corn meal manufacture,the breakage losses with present procedure is much higher due to moreextensive pneumatic cleaning exposure. In corn flake plants, presentlosses amount to 8 lbs. per bushel of corn. This 8 lbs. of broken cornkernels has to be channelled into feed instead of corn flakes. With theprocess of this invention, corn flake plant corn unloading breakagelosses are reduced to 0.25 lbs. per bushel.

While this invention lends itself particularly well to corn and soyabeans, the process can also be exploited in many leguminous orvegetable-kernel materials. Examples of other materials suitable forapplication with my process are wheat, barley, oats, rye, rice, peas,beans and various seeds. In place of air heated by steam coils, fluegases heated by oil burners or any other means may be used. Where theclean grain is subjected to wet processing, one may use process waterscontaining small amounts of processed grain or grain fractions. Thepressure on the water nozzles and the rate of water delivery from saidnozzles can be widely varied, depending upon the particular seed orkernel material being handled.

While I have illustrated and described a precise arrangement forcarrying the invention into effective use, this is capable of manyvariations, modifications and alterations without departing from thespirit of the invention. I, therefore, do not wish to be limited by thedescription and drawings forming a part of this specification, butdesire to avail myself of such changes as may fall within the spirit andscope of the appended claims.

I claim:

1. Method of unloading and washing grain which comprises injecting intoa bulk mass of said grain a powerful stream of water with forcesufficient to slush said grain from said mass to produce a flowingmixture of grain and water; screening the resulting mixture underconditions permitting passage of the grain and water but restraining theobjects larger than the kernels of the grain; thereafter straining thegrain from the Water and washing the strained grain with jets of waterhaving sufficient force to remove therefrom adherent small particulatematter, and thereafter drying the washed and cleaned grain.

2. Apparatus for unloading grain from containers thereof which comprisesmeans for directing a stream of Water under pressure into saidcontainers to slush the grain therefrom in the form of a mixture ofgrain and water; a coarse screening means into which said mixture isdirected for separating particulate matter larger than the kernels ofsaid grain from the said mixture; means beyond said coarse screeningmeans and fed thereby for separating the initial water from said grain,including shaking screens having openings small enough to retain thegrain thereon; means for directing jets of clean water upon the retainedgrain to wash it; means for conveying the washed grain, includingmagnetic separating means for removing magnetically attracted materialstherefrom; and a vertical grain conveyor for elevating said grain andmeans on said conveyor for substantially horizontally passing heatedgases athwart the conveyor and over and around the grain thereon to drythe same.

3. The apparatus as per claim 2 in which the container is a box car.

4. The apparatus as per claim 3 in which means are provided forelevating the side of the box car opposite the door thereof so as tofacilitate the flow of the water-grain mixture from the door of saidcar.

References Cited in the file of this patent UNITED STATES PATENTS1,139,484 Bryan May 18, 1915 1,461,067 Moser July 10, 1923 1,716,240Postweiler June 4, 1929 OTHER REFERENCES Coal Age, January 1948, pages64-69.

